The present invention relates to architectural lighting fixtures and more particularly to hardware for suspending architectural lighting fixtures below a "drop ceiling" such as an acoustical tile grid ceiling or a drywall ceiling.
Architectural lighting fixtures installed in commercial buildings typically must be suspended below a drop ceiling structure which provides a finished ceiling but which itself cannot bear the weight of the lighting fixtures. In such environments, the lighting fixtures must be suspended from the structural components of the building above the drop ceiling. This necessitates drilling a hole through the finished ceiling through which the suspension hardware for the lighting fixture can be installed. For example, when installing a linear lighting system, the fixture components making up the system are typically suspended from a number of different suspension points by means of suspension cables connected at the finished ceiling to 1/4-20 threaded support rods. The support rods, which are secured to the building's structural components above the finished ceiling, hang downward so that their ends project into holes drilled into the finished ceiling at pre-defined support locations. In this manner, the finished ceiling does not bear the weight of the fixtures, but rather the weight of the fixtures is taken up by the overhead support rods. What is seen at the finished ceiling are junctions between the cable attachment hardware and the hidden support rods.
A problem with such ceiling junctions is that the junctions are often unsightly. They can also damage the surrounding ceiling material. For example, a hole may be drilled in the ceiling material having visible ragged edges, or the ceiling material, which may be a relatively soft material such as acoustical tile, may be torn, abraded, or crushed around the junction during the installation process or when a pendulum motion is imparted to the suspended fixture components. Furthermore, the holes that need to be drilled through the finished ceiling to accommodate the junctions are frequently slightly mislocated such that the junctions tear the ceiling material when the suspension cables and rods, under the weight of the fixtures, tend to align themselves.
The present invention overcomes the problem of providing aesthetically pleasing ceilings junctions for suspended architectural lighting fixtures by providing a self-tapping sleeve that permits a suspension junction in the finished ceiling to be created that has a pleasing finished appearance. The self-tapping sleeve of the invention is easy to properly position and install and will act to protect adjacent ceiling material from possible damage in the event the suspension hardware is caused to move in sideward motion, for example, during an earthquake or when a workman jostles the lighting fixtures during installation or relamping.